1. Field of the Invention
The present invention relates to a brushless motor, in more detail, a structure of a brushless motor that is used in a fluid pump pumping and discharging fluid, and a fluid pump using the brushless motor.
2. Description of the Related Art
In fluid pumps pumping and discharging fluid, fuel pumps that are mounted in a fuel tank of vehicles and pump fuel have been known, and typical DC motors equipped with a common commutator have been used in the fuel pumps in the related art.
The DC motors are configured to be supplied with needed electricity for driving a commutator and a brush, in which the durability has a basic problem due to loose contact by wear of the brush and the method of supplying electricity by using contact of the commutator and the brush consumes a large amount of electric power in operation by reducing the efficiency of the DC motors, thereby reducing energy efficiency.
Brushless motors has been proposed to overcome the defects of the DC motors and an interior permanent magnet brushless motor generally has a small gap between a stator and a rotor because the small gap between the stator and the rotor is advantageous in driving the motor, which is inadequate to a fluid pump that should pump and flow fuel between a stator and a rotor.